Arsenal were stunned by a brilliant Brighton as Fabian Hurzeler's men romped to a 3-0 win to end the Gunners' unbeaten start to the Premier League season.
The reigning champions found themselves a goal down after a stunning strike from Pascal Gross after half an hour and that deficit doubled when Charalampos Kostoulas scored right on half time with another excellent goal.
Chema Andrés then scored Brighton's third goal from a corner to put the game to bed for the home side.
You can read how it happened on ESPN below.
Fresh from a 4-2 midweek Carabao Cup win over Ipswich Town, Mikel Arteta's side could have finished the day three points clear of Manchester City, who play on Sunday.
Brighton meanwhile were riding the high of a comeback win at Old Trafford and managed to keep the momentum rolling at home.
A Max Dowman double inspired Arsenal against Ipswich in a game where a number of Arteta's second-choice players got a run out, impressing in the process.
This fixture came after Brighton boss Fabian Hürzeler aimed a dig at Arsenal last season, saying "only one team tried to play football" while he also accused the Gunners of "making their own rules."
Arteta appeared to bury the hatchet in the build up to this one however, saying it is "all in the past" and that he has "huge respect" for Hürzeler.
This past week, Brighton were 2-0 down at the break against Manchester United, but a sensational second-half turnaround capped off by Maxim De Cuyper's winner saw them progress in the Carabao Cup.
The result ended a six-game winless streak for Brighton against Arsenal at home.
